A hybrid powertrain has an engine, an input member, an output member, and a stationary member, and includes a single planetary gear set having a first, a second, and a third member. The input member is connected for common rotation with the engine. The output member is connected for common rotation with the second member. A first and a second motor/generator are provided, as well as five torque-transmitting mechanisms, including only one brake. The torque-transmitting mechanisms are engagable in different combinations to establish at least two electric-only operating mode, at least two engine-only operating mode, and at least three electrically-variable operating modes. In one embodiment, an electric torque converter operating mode is provided, and may be the default mode in case of motor/generator failure.